The invention relates to small electric motors and particularly to double insulated motors and double insulated apparatus. The term "double insulated apparatus" refers to apparatus having two independent and redundant insulating layers. Apparatus incorporating double insulation typically do not have a separate ground pin on the electric plug. Applications for the present invention include vacuum cleaners, lawn mowers, hair dryers and other motor driven appliances.
The prior art includes open ended plastic sleeves that are disposed around the output shaft of typical prior art double insulated motors. Such sleeves typically will engage a cylindrical output shaft. They will not, however, provide both the necessary insulation and also conform to shafts having an irregular exterior surface.
Conventional coupling methods do not allow the use of sleeves as shown in FIG. 1 on intricate coupling forms because the sleeve will not conform to the geometry of the drive surface.
A primary object of the invention is to provide apparatus that will provide better insulation for the output shaft of an associated motor.
It is an object of the invention to provide apparatus that will in various form facilitate the physical coupling of a plurality of mechanisms to the motor.
It is another object of the invention to provide apparatus which is inexpensive to manufacture as well as requires a minimum of labor to install.
Still another object of the invention is to provide apparatus that will not only provide the necessary double insulation while still being capable of being formed in a variety of shapes.